1. Field of the Invention
The subject invention relates generally to a bearing assembly, and more specifically to a roller bearing assembly for rotatably supporting a first shaft member relative to a second shaft member.
2. Description of the Prior Art
Bearings often include an inner race, an outer race, and a plurality of rollers disposed between the inner race and the outer race to provide rolling engagement between the inner race and the outer race. The rollers are often supported by a cage disposed between the inner race and the outer race. The cage defines a plurality of openings, with one of the rollers disposed within each of the openings. The inner race and the outer race each define a plurality of grooves, with one of the rollers disposed within each of the grooves.
It is known to manufacture the inner race and the outer race from a polymer material, i.e., a plastic. When the inner race and the outer race are manufactured from a polymer, they are often formed in a die. However, when formed in a die, the grooves of the inner race and the outer race are required to be shallow to allow for removal of the inner race and the outer race from the die. The shallow grooves limits the polymer bearing to a low axial load capacity. Alternatively, it is known to mold the inner race and the outer race, and then machine the grooves into the inner race and the outer race. While machining the grooves after molding the inner race and the outer race permits deeper grooves, and thereby a higher axial load capacity, the machining process removes the outer layer of the polymer material, i.e., the skin of the polymer. Removal of the outer layer of the polymer material reduces the wear resistance of the polymer, thereby reducing the life expectancy of the bearing assembly.